To ensure safety, what should a diver do if visibility decreases underwater?

When visibility decreases underwater, staying close to a guideline or buddy is the best practice for ensuring safety. This approach allows a diver to maintain orientation and avoid getting disoriented in low-visibility conditions. Guidelines provide a physical reference point, which can help divers navigate back to the entry point or the surface safely. Additionally, remaining close to a buddy enhances mutual support, allowing divers to assist each other if needed, especially in environments that may become more challenging to navigate as visibility diminishes.

The other options have limited effectiveness in maintaining safety during low-visibility conditions. Increasing equipment weight could affect buoyancy and control without addressing the core issue of navigation and orientation. Activating an emergency beacon may not be necessary unless the situation becomes dire, and relying solely on emergency signals does not help in managing the immediate visibility problem. Abruptly aborting the dive may not be the safest choice either, as divers should prioritize navigating safely and returning to a familiar location rather than leaving the water hastily without a plan.